The present invention relates to vibrating type ice detectors for use with aircraft and in any other locations where the detection of ice is of importance. More particularly, the present invention relates to ice detector configurations that increase the critical temperature limit of an ice detector probe to provide earlier ice detection.
Existing ice detectors are useful in near freezing temperature conditions for detecting the formation of ice on the detector, and providing a warning of the ice formation prior to the formation of ice on the wings, engine nacelles, and other control surfaces of an aircraft. A frequently used type of ice detector is a vibrating ice detector. Vibrating type ice detectors use a vibrating probe upon which ice accumulates. Typically, the probe is a cylindrical probe having a hemispherical end. Examples of vibrating type ice detectors are described, for example, in U.S. Pat. No. 3,341,835 entitled ICE DETECTOR by F. D. Werner et al.; U.S. Pat. No. 4,553,137 entitled NON-INSTRUSIVE ICE DETECTOR by Marxer et al.; U.S. Pat. No. 4,611,492 entitled MEMBRANE TYPE NON-INTRUSIVE DETECTOR by Koosmann; U.S. Pat. No. 6,269,320 entitled SUPERCOOLED LARGE DROPLET ICE DETECTOR by Otto; and U.S. Pat. No. 6,320,511 entitled ICE DETECTOR CONFIGURATION FOR IMPROVED ICE DETECTION AT NEAR FREEZING CONDITIONS by Cronin et al., which are herein incorporated by reference in their entirety.
The ability of ice detectors to provide a warning of ice formation prior to formation of ice on the wings, engine nacelles, or other control surface of an aircraft is dependent upon the critical temperature of the ice detector probe and the critical temperature of the aircraft wings or control surface. The critical temperature is defined as the ambient static temperature at or above which none of the supercooled liquid water droplets in a cloud will freeze when they impinge on a structure. Stated another way, the critical temperature is the temperature above which no ice will form (or below which ice will form) on a structure (such as an aircraft wing or an ice detector probe) given its configuration and other atmospheric conditions. The critical temperature can be different for different structures, and specifically for a typical airfoil configuration and for a conventional ice detector, at the same airspeed.
Since the critical temperature of an ice detector probe is the temperature below which ice will begin to form on the probe, thus defining the upper temperature limit at which the ice detector will not detect icing conditions, it is of significant interest in the design of ice detectors. Ensuring that the critical temperature of the ice detector probe is above the critical temperature of the wings or other control surfaces of an aircraft is a continuing challenge, particularly with newer airfoil designs. Therefore, a vibrating type ice detector having a probe with an increased critical temperature would be a significant improvement in the art. Other ice accretion improving features would similarly be significant improvements in the ice detector art.
The present invention addresses one or more of the above-identified problems and/or provides other advantages over prior art ice detectors.